Stock feeding means for rotary printing machine



June 4, 1957 J. A. BURKE, JR 2,794,390

STOCK FEEDING MEANS FOR ROTARY PRINTING MACHINE Filed March 20, 1953INVENTOR ATTORNEYS United This invention relates to methods and meansfor printmg and, more particularly, to such methods and means forprinting on a multiply surface such as the back of an envelope.

Printing across the entire rear face of envelopes has becomeincreasingly popular during recent years. The problems attendingprinting across an entire surface comprising a plurality of flaps whichpresent an uneven surface have been solved, at least in part, by using arelatively soft blanket on the printing cylinder so that the impressionmay be made completely up to the shoulders presented by overlying flaps,and there will be no unprinted portions of the surface. To print over anentire surface, however, it is necessary to dispense with the usualgrippers which, on conventional presses, engage the leading edge of asheet to be printed and hold it for proper registration as it is drawnbetween the printing and pressure cylinders. The conventional use ofpairs of grippers is not feasible even where a narrow border around theperiphery of the sheet is to be left unprinted. The conventionalgripping means are too large for this purpose. Printing without grippershas presented many problems with regard to proper registration of thesheet to be printed. A further problem has confronted those who haveattempted to print without grippers. it is well known that material tobe printed has a tendency to wrap around the printing roll, and thegrippers have served the purpose of stripping the sheet from the roll.Consequently, when grippers are dispensed with the stripping problem ispresent.

The object of the present invention is to provide methods and means forsecuring accurate registration of the sheet to be printed without theneed for gripping the sheet between pairs of jaws, and for maintainingthat registration throughout the printing cycle.

A further object is to provide means to align the sheet before the sheetreaches the nip of the printing and pressure cylinders, and to hold thatalignment during the passage of the sheet between these rolls.

A still further object of the invention is to provide means forstripping the sheet from the printing roll without the need for grippingelements.

Other objects of the invention will appear from the followingdescription of practical embodiments thereof when taken in conjunctionwith the drawings which accompany, and forma part of, thisspecification.

' In the drawings:

Fig. l is a somewhat schematic View of the feed rolls, printing andimpression rolls, and paper guide chain of an offset press embodying theprinciples of the present invention;

Fig. 2 is a vertical transverse section through the structure shown inFig. 1, and is taken on the line 22 of Fig. 1;

'Fig. 3 is a View similar to Fig. 1 showing a modified form of the meansfor controlling the stock in its passage through the machine; Fig. 4isan enlarged, vertical sectional view of portions of the printing andpressure rolls and the stock guide atent chain just prior to the sheetreaching the nip of'the rolls;

- vention, no showing'has been made of an entire printing press, andthose portions of the machine which are shown are illustrated more orless schematically.

in general, the invention consists in feeding the leading edges ofasheet of desired stock against a travelling aligning means andmaintaining the sheet in contact with the aligning means during itsentire passage between the printing and pressure cylinders. It furtherconsists in a machine for carrying out this method, and in the provisionof aligning means which will also serve to strip the stock from theprinting cylinder.

Referring to'the drawings in detail, and first adverting to that form ofthe invention shown in Figs. 1 and 2, there is shown a conventionalpressure cylinder I mounted upon a shaft 2, which shaft is to bejournalled in the usual frame (not shown) and driven by conventionalmeans to rotate the cylinder. Directly beneath the pressure cylinderthere is a printing cylinder 3 mounted upon a shaft 4, also suitablyjournalled and driven. The printing cylinder is provided with arelatively thick blanket 5 of soft material such as rubber, which takesthe image from the usual plate (not shown) for transfer to the stock.The printing and pressure cylinders are mounted in the usual manner sothat the periphery of the pressure roll is in contact with the blanket 5on the printing cylinder duringthat portion of the rotation of thecylinders when the blanket is passing beneath the pressure cylinder.

In front of the cylinders 1 and 3 are a pairof feed rollers 6 and 7.These feed rollers are located in advance of the cylinders, but closeenough so that the leading edge of the stock being fed will be grippedby the nip of the cylinders before the trailing edge is released fromthe nip of the feed rolls.

At either side of the printing cylinder guide chains 8 are arranged. Thechains pass over sprockets 9 at the front, and sprockets 10 at the rearor delivery end of the machine. Sprockets 9 are mounted upon shaft 4,which carries the printing cylinder, and sprockets 10 are mounted upon ashaft 11. The sprockets are arranged so that the flights of the endlesschain are inclined, and the top flight has its top surface substantiallytangential to the cylinders 1 and 3 at the nip between the cylinders. v

There are two guide chains 8 which are spaced apart a distance slightlygreater than the length of the pressure and printing cylinders. Thechains carry a bar 12 which bridges the distance between the two chainsand has its ends attached to the chains. The bar carries several.horizontally extending arms 13. These arms are spaced apart along thebar and each has a vertically positioned shoulder 14, which forms anabutment for the stock. As the shoulders are in alignment, they formguides to properly position the stock before its entry between the nipof the printing and pressure cylinders. The fingers have overlyingforwardly extending portions which form horizontal stock-engagingsurfaces 15 to hold the forward edge of the stock against the blanket 5on the printing cylinder asthe stock enters the nip of the cylinders.The guide arms 13 also have upward extensions 16 which rise above theplane of the arms, for purposes to be described. The printing cylinderhas a longitudinal groove 17 in-its periphery and the pressure cylinder.has a similar groove 18 to receive the bar and guide arms to permitthem to pass the cylinders during rotation.

A plurality of recesses 19 are formed in the trailing edge of the groove18 in cylinder 1, which recesses are also open to the surface of theroller. Recesses 19 receive the upward extensions 16 of the guide arms,and are dimensioned so as to be of approximately the same Width as theextensions 16. The depth of the recesses from the surface of thecylinder is exactly the depth of extensions 16 to the stock-engagingsurfaces 15, so that when the extensions are in the recesses, thesurfaces 15 are flush with the peripheral surface of the pressurecylinder.

As the bar 12 is connected to opposite links of the chain 8, theposition of the bar and the guide. arms carried by the bar will alwaysbe tangential to the arcuate path of travel of the bar when passingaround sprockets 9. As the operative end of the arms, having theshoulders this end of the arms will be spaced an appreciable distanceoutward from the orbit of the chain during the passage of the chainaround the sprockets. Thus, as the 19 and the shoulders 14 willbridgethe gap between the surface of the pressure cylinder .1 and the blanketcarried on the printing cylinder. This is the position of the partsillustrated in Fig. 4 of the drawing. When'in this position theshoulders 14 will form stops to position the forward edge of the stockbeing fed to the cylinders which position the-leading edge of theprinting blanket. As the cylinders continue their rotation and reach thepoint'of nip, the forward edge of the stock will be firmly placedagainst the blanket along its full length. The stockengaging surfaces 15of the guide arms will substantially complete the surface of thepressure cylinder and as the extension 16 of the arms is against the topof the recess, equal pressure will be applied'along the full leadingedge of the stock.

The stock is guided'in its passage into contact with the guide arms bymeans'of the usual guide 20 placed between feed rollers and the printingand pressure cyl- 'inders. As is customary, the feed rollers operatewith a varying speed, and when stock passes between them their speed isincreased so that the leading edge of the stock approaches and contactsthe shoulders of the guide arms. As the stock is moving slightly fasterthan the speed of the guide arms 13, the stock will be pressed againstthe shoulders and held there until the stock is engaged between the nipof the cylinders. Due to the fact that the chains carrying the guidearms are moving at the speed of the printing and pressure cylinders andstock will be held in positive registration with these cylindersthroughout the printing cycle, and due to the velocity of the stock uponleaving the cylinders, it will be maintained in engagement with theguide arms until the delivery end of the machine is reached.

In Figs. 3 and 4 of the drawings a slightly modified structure has beenshown. In this form of the invention it is necessary that a strip ofinsulating material 21 be positioned between the guide fingers and thebar 12. In order to permit the guide arms to have a positive hold I onthe stock, the guides are given a charge of static electricity beforethe stock is brought in contact with 'them. This will permit the guidearms to strip the stock from the printing cylinder and, therefore, allowthe use of much heavier printing inks. To obtain the static charge, apiece of cats fur 22 may be positioned at any convenient'point on themachine so that it may be contacted by the upward extensions 16 on theguide arms.

The fur is shown as mounted beneath the bottom flight of the chain nearthe front of the-machine, so that the charge is given to the arms justprior to their engagement with the stock. As shown in Fig. 3, a tinselribbon 23 maybe used at the rear of the machine so that a guide armswill contact it in passing around the rear sprockets, to discharge thestatic charge and release the stock from the guide arms, so that it maydrop into a basket or other alignment of the stock will be maintainedthroughout the 14 and stock-engaging surfaces 15, is beyond the bar, 1

1. Printing apparatus comprising a printing cylinder.

and a pressure cylinder, 'a blanket on said printing cylinder, saidcylinders mounted for rotation so that the pressure cylinder will be insurface contact with said blanket once each cycle of rotation, feedrollers to. one side of said cylinders at a distance from said cylindersless than the length of thestock to be printed, chains at either side ofsaid printing cylinder mounted upon sprockets concentric to saidprinting cylinders and sprockets to the opposite side of said cylindersfrom said feed rollers, a bar bridging said chains and carryingtransversely aligned guide arms to be contacted by and align the stock,means to rotate said cylinders at the same surface speed and said chainsat a linear speed equal to the surface speed of said cylinders, saidcylinders having transverse grooves therein to permit passage of thesaid bar and fingers through the nip of the cylinders, said pressurecylinder having a plurality of recesses opening'to said groove and thesurface of said pressure cylinder, said recesses being aligned with thepath of travel of said guide arms, said arms having vertical shouldersto align said stock for registration with the printing cylinder blanket,horizontal overlying lips to than the length of the stock to be printed,a pair of endless chains one on either side of said printing couple,sprockets concentric to the printing cylinder and rotatable therewithand sprockets on the opposite side of said printing couple from saidfeed rollers, said chains passing around said sprockets, a barpositioned transversely of said chains and having its ends connected toone link in each chain, a plurality of arms spaced along said bar andextending rearwardly with respect to the direction of travel of saidchains, each of said arms having a shoulder at right angles to the chainlinks to which said bar is attached positioned rearwardly of said linksand in the projected plane of the leading edge of said blanket when saidlinks are on the sprockets concentric to the printing cylinder and a lipextending rearwardly from said shoulder to lie tangentially to thesurface of said blanket as said links leave the sprockets concentric tothe printing cylinder, whereby said shoulders will form guide stops forstock at the leading edge of said blanket when said links are on thesprockets concentric to said printing cylinder and said overlying lipswill press --the leading edge of stock into surface engagement with saidblanket as said links leave said sprockets concentric to said pn'ntingcylinder.

3. Printing apparatus comprising, a printing cylinder having a blanketthereon and a pressure cylinder arranged as a printing couple, a pair offeed rollers positioned in front of the nip of the printing couple adistance less than the length of the stock to be printed, a travellingguide movable in the direction of stock travel at the abutting surface,said guide and said printing couple having their respective movementstimed to bring the abutting surface of said guide into alignment withthe leading edge of the blanket on said printing cylinder prior to saidleading edge reaching the nip of said printing couple, means carried bysaid guide to overlie the leading edge of the upper surface of stockagainst said abutting surface and on said blanket, and means on saidprinting couple to press said stock overlying means against the uppersurface of said stock, said guide being mounted between a pair ofendless chains passing around front and rear sprockets, said frontsprockets being positioned concentric to said printing cylinder, andsaid rear sprockets positioned on the opposite side of said printingcouple from said feed rollers.

4. Printing apparatus comprising, a printing cylinder having a blanketthereon and a pressure cylinder arranged as a printing couple, a pair offeed rollers positioned in front of the nip of the printing couple adistance less than the length of the stock to be printed, a travellingguide movable in the direction of stock travel at the surface speed ofsaid printing couple and having a stock abutting surface, said guide andsaid printing couple having their respective movements timed to bringthe abutting surface of said guide into alignment with the leading edgeof the blanket on said printing cylinder prior to said leading edgereaching the nip of said printing couple, means carried by said guide tooverlie the leading edge of the upper surface of stock against saidabutting surface and on said blanket, and means on said printing coupleto press said stock overlying means against the upper surface of saidstock, said guide being mounted between a pair of endless chains passingaround front and rear sprockets, said front sprockets being positionedconcentric to said printing cylinder, and said rear sprockets positionedon the opposite side of said printing couple from said feed rollers,said guide comprising a bar bridging said chains and a plurality ofguide arms positioned in alignment on said bar.

5. Printing apparatus comprising, a printing cylinder having a blanketthereon and a pressure cylinder arranged as a printing couple, a pair offeed rollers positioned in front of the nip of the printing couple adistance less than the length of the stock to be printed, a travellingguide movable in the direction of stock travel at the surface speed ofsaid printing couple and having a stock abutting surface, said guide andsaid printing couple having their respective movements timed to bringthe abutting surface of said guide into alignment with the leading edgeof the blanket on said printing cylinder prior to said leading edgereaching the nip of said printing couple, means carried by said guide tooverlie the leading edge of the upper surface of stock against saidabutting surface and on said blanket, and means on said printing coupleto press said stock overlying means against the upper surface of saidstock, said guide being mounted between a pair of endless chains passingaround front and rear sprockets, said front sprockets being positionedconcentric to said printing cylinder, and said rear sprockets positionedon the opposite side of said printing couple from said feed rollers, andmeans to impart a static charge to said guide prior to the engagement ofthe stock therewith.

6. Printing apparatus comprising, a printing cylinder having a blanketthereon and a pressure cylinder arranged as a printing couple, a pair offeed rollers positioned in front of the nip of the printing couple adistance less than the length of the stock to be printed, a travellingguide movable in the direction of stock travel at the surface speed ofsaid printing couple and having a stock abutting surface, said guide andsaid printing couple having their respective movements timed to bringthe abutting surface of said guide into alignment with the leading edgeof the blanket on said printing cylinder prior to said leading edgereaching the nip of said printing couple, means carried by said guide tooverlie the leading edge of the upper surface of stock against saidabutting surface and on said blanket, and means on said printing coupleto press said stock overlying means against the upper surface of saidstock, said guide being mounted between a pair of endless chains passingaround front and rear sprockets, said front sprockets being positionedconcentric to said printing cylinder, and said rear sprockets positionedon the opposite side of said printing couple from said feed rollers,said guide comprising a bar and a plurality of arms projectingtherefrom, each of said arms having said stock abutting and stockoverlying surfaces, and means to impart a static charge to said guideprior to the engagement of the stock therewith.

7. Printing apparatus comprising, a printing cylinder having a blanketthereon and a pressure cylinder arranged as a printing couple, a pair offeed rollers positioned in front of the nip of the printing couple adistance less than the length of the stock to be printed, a travellingguide movable in the direction of stock travel at the surface speed ofsaid printing couple and having a stock abutting surface, said guide andsaid printing couple having their respective movements timed to bringthe abutting surface of said guide into alignment with the leading edgeof the blanket on said printing cylinder prior to said leading edgereaching the nip of said printing couple, means carried by said guide tooverlie the leading edge of the upper surface of stock against saidabutting surface and on said blanket, and means on said printing coupleto press said stock overlying means against the upper surface of saidstock, said guide being mounted between a pair of endless chains passingaround front and rear sprockets, said front sprockets being positionedconcentric to said printing cylinder, and said rear sprockets positionedon the opposite side of said printing couple from said feed rollers,said guide comprising a bar and a plurality of arms projectingtherefrom, each of said arms having said stock abutting and stockoverlying surfaces, and a piece of cats fur positioned to be contactedby said arms prior to engagement with said stock to impart a staticcharge to said arms.

8. Printing apparatus comprising, a printing cylinder having a blanketthereon and a pressure cylinder arranged as a printing couple, a pair offeed rollers positioned in front of the nip of the printing couple adistance less than the length of the stock to be printed, a travellingguide movable in the direction of stock travel at the surface speed ofsaid printing couple and having a stock abutting surface, said guide andsaid printing couple having their respective movements timed to bringthe abutting surface of said guide into alignment with the leading edgeof the blanket on said printing cylinder prior to said leading edgereaching the nip of said printing couple, means carried by said guide tooverlie the leading edge of the upper surface of stock against saidabutting surface and on said blanket, and means on said printing coupleto press said stock overlying means against the upper surface of saidstock, said guide being mounted between a pair of endless chains passingaround front and rear sprockets, said front sprockets being positionedconcentric to said printing cylinder, and said rear sprockets positionedon the opposite side of said printing and pressure cylinders from saidfeed rollers, said guide comprising a bar and a plurality of armsprojecting therefrom, each of said arms having said stock abutting andstock overlying surfaces, insulating material between said arms and saidbar, and means to impart a static charge to said arms prior to theengagement of the stock therewith.

References Cited in the file of this patent UNITED STATES PATENTS2,208,043 Ormond July 16, 1940 2,387,750 Davidson Oct. 30, 19452,406,205 Davidson et al. Aug. 20, 1946 2,576,882 Koole et a1 Nov. 27,1951

